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'(No Model.)

0. A. ENHOLM & T. 11.33011.

THERMOSTATIG FIRE ALARM Fig-1- I71 U671 to 715*; gm Q;

UNITED STATES PATENT OFFICE.

OSCAR. A. ENHOLM AND THOMAS II. BECK, OF NElV YORK, .N. Y.

THERMOSTATlC FlRE-ALARM.

SPECIFICATION forming part of Letters Patent No. 581 ,544, dated April 27,- 1897.

Application filed-November 23, 1896. Serial No. 613,072. (No model.)

To all whom it may concern:

Be it known that we, OSCAR A. ENHOLM and THOMAS H. BECK, citizens of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improve ments in Thermostatic Fire-Alarms, of which the following is afull, clear, and exact specification.

This invention relates to thermostatic fire-' alarms; and its object is to construct an, alarm which shall be eflicient in operation, shall be self-con tained,and can be placed and removed at will without the usual multiplication of wires or mechanical apparatus necessary with the ordinary fire-alarm'of commerce. To accomplish this, we propose to place all the needed parts comprising the apparatus in and on acomparatively smallbox which may be adapted to be hung upon the wall or'stand upon a shelf or other convenient place which shall be capable of continuous and successive use without reconstruction or alteration.

A further feature of the invention is the construction of a thermostat in which the electric contact is dependent upon the efiect of heat upon a metallic surface covered with wax or paraffin.

Generally speaking, the apparatus maybe said to consist of abox containing an electric battery, an electric bell, and connecti rig-wires,

the same being placed in the box. On a con venient part of the box is located a thermostat, and onthe front side of the box is a testing-button for ascertaining the condition of the battery and bell.

The apparatus also com prehends a circuitcloser comprising a depressed disk containing fusible material and a spring adapted torest thereon, the spring and disk being connected with the respective terminals of the circuit. our invention will be more fully understood by referring to the description of the form thereof illustrated in the accompanying drawings, in which- Figure 1 represents a front view, partly in section, of a device embodying the invention; and Fig. 2 isa diagram of the parts, showing the circuits. Fig. 3 is a sectional side view of Fig. 1. v

In the drawings, Ais a metallic spring, and

spring. The waxor parafiin is representedin j the drawings by the reference-letter b.

It is to be understood that the term wax used herein and in the claims appended here- 'to is intended to cover all formsof wax or paraffin or similar substances.

0 is a shaft. upon which the disk at is carried,

and d is a busheling or bearing to hold shaft,

c in upright position, the-shaft being capable of rotation therein.

E represents a battery of any suitable type, and F a bell or other alarm. \Vire e connects the battery, wire f connects the other terminal of the battery with the bell, wire 9 connects the bell with spring A, and spring A .normally rests upon the parafiin b upon disk a, thereby forming a circuit interrupted by the parafiin or wax.

h represents a circuit-closing device, and i and 7c, respectively,.represent wires connecting the terminals of the circuit-closing device with thebattery and the bell.

The operation of the above-described apparatus is substantially as follows: At the normal temperature the wax on disk a prevents contact betwcen the point of spring A and disk a, thereby maintaining a break in the current. If the temperature rises to a dangerous degree-say, for instance, 125 Fahrenheit-the wax in disk' amelts, allowing the contact-point of spring A- to press down upon the metallic surface of the disk. The circuit is thus completed and the alarm will sound. Should the wax melt from any cause disk a through shaft 0 with one terminal .of i v other than that of an actual fire in the apart- It may be spring should be light and have a curved surface resting against the wax, substantialy as closers in various parts of the building or apartment. I

A further ad vantage and improvement attained by us is the construction of an apparatus of this character whichmay be compactly embodied in one box or receptacle.

Heretofore such apparatus has been cumbersome and diflicult to install by reason of the fact that its various parts have been located at different places. A

We have constructed an apparatus, as illustrated in Figjl, wherein the various parts are close together. M represents a suitable casing within which is mounted the alarm F. 'n is a suitable opening in the casing through which the alarm partly projects, the magnets thereof being located inside the casing. By this arrangementthe magnets and operating parts of the alarm are protected from dust, &0., and the alarm itself gives forth the same clear and loud tone as when located entirely, upon the outside of the casing. Upon the outside of the box is placed the wax contact device, the latter being protected from dust, &c., by 'a suitable covering-plate in. The circuit-wires are arranged substantially as hereinbefore described.

It is to be understood that we do not herein limit ourselves to the exact construction shown and described, as it is obvious that the various parts may be altered, reversed, or equivalents substituted therefor without departingfrom the spirit or terms of our invention.

Having thus described our invention, we claim 1. In an electric thermostatic alarm, the

combination with the circuit, of a rotatable recessed disk containing fusible material,

and a spring, one end of which rests on the surface of the wax, said disk and said spring being connected with theterminals of said circuit, for the purpose set forth.

2. In an electric thermostatic alarm, the

combination'with the circuit, of a circular rotatably mounted disk having upwardlyturned edges, a body of fusible material contained in said disk, and a spring normally resting upon said fusible material, whereby different portions of said body of fusible material may be brought under the spring, said spring and said disk being connected with the respective terminals of the circuit, substantially as described. a

3. In a thermostatic alarm, the combin a tion of a casing, an openingtherein, an-al'armj in said casing extending partly through said opening, a battery in said casing, a rotatable recessed disk supported upon the outside of said casing, fusible material contained in said recessed disk, a spring normally resting upon said fusible material, acovering-plate over said diskand spring, and connections between said alar n, spring, disk and battery to complete an electric circuit thercthrough, substantially as described.

In testimony whereof we affix our signatures in presence of two witnesses.

OSCAR A. ENll'OLM. THOMAS H. BECK.

\Vituesses:

V. EDWARDS, 'M. A. RYAN. 

